Leaf rust resistance gene Lr1, isolated from bread wheat (Triticum aestivum L.) is a member of the large psr567 gene family
Leaf rust resistance gene Lr1, isolated from bread wheat (Triticum aestivum L.) is a member of the large psr567 gene family
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DOI：
10.1007/s11103-007-9201-8
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发表时间：
2007-09-01
影响因子：
5.1
通讯作者：
Jordan, Mark C.
中科院分区：
文献类型：
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作者：
Cloutier, Sylvie;McCallum, Brent D.;Jordan, Mark C.
在六倍体小麦中，抗叶锈病基因Lr 1位于染色体5D长臂的远端。为了克隆该基因，对来自感病品种AC Karma和抗性品系87 E03-S2 B1之间的杂交的F-1衍生的双单倍体群体和重组自交系群体进行了对携带无毒基因Avr 1的小麦柄锈菌小种1-1 BBB的抗性表型分析。利用微卫星、抗性基因类似物（RGA）、BAC末端（BE）和低通（LP）标记构建了Lr 1基因座的高分辨率遗传图谱。通过从已知具有Lr 1的栽培品种Glenlea中筛选六倍体小麦BAC文库，构建了该基因座的物理图谱。该位点包含来自与RFLP标记Xpsr 567相关的基因家族的三个RGA。开发了对每种parabacterium特异的标记。Lr 1与RGA 567 -5分离，而其它两个RGA观察到重组体。用RGA 567 -5转化感病品种菲尔德，证明它对应于Lr 1抗性基因。此外，还通过病毒诱导的基因沉默证实了候选基因。从抗Avr 1的转基因株系T（0）-938获得的20个T（1）株系对Avr 1的抗性、部分抗性和感病分离，对应于1：2：1的比例。转基因的存在和表达与表型相关。因此，Lr 1所表达的抗性表型似乎依赖于接合性状态。用16个强毒和无毒的锈菌分离物进一步测试了转基因和不转基因的T（3）-938姊妹系。锈蚀反应与Lr 1的预期一致，从而为RGA 567 -5的Lr 1鉴别提供了额外证据。Lr 1的序列分析表明，它与先前分离的Lr 10和Lr 21基因无关，并且与这些基因不同，它是一个大基因家族的一部分。
In hexaploid wheat, leaf rust resistance gene Lr1 is located at the distal end of the long arm of chromosome 5D. To clone this gene, an F-1-derived doubled haploid population and a recombinant inbred line population from a cross between the susceptible cultivar AC Karma and the resistant line 87E03-S2B1 were phenotyped for resistance to Puccinia triticina race 1-1 BBB that carries the avirulence gene Avr1. A high-resolution genetic map of the Lr1 locus was constructed using microsatellite, resistance gene analog (RGA), BAC end (BE), and low pass (LP) markers. A physical map of the locus was constructed by screening a hexaploid wheat BAC library from cultivar Glenlea that is known to have Lr1. The locus comprised three RGAs from a gene family related to RFLP marker Xpsr567. Markers specific to each paralog were developed. Lr1 segregated with RGA567-5 while recombinants were observed for the other two RGAs. Transformation of the susceptible cultivar Fielder with RGA567-5 demonstrated that it corresponds to the Lr1 resistance gene. In addition, the candidate gene was also confirmed by virus-induced gene silencing. Twenty T (1) lines from resistant transgenic line T (0)-938 segregated for resistance, partial resistance and susceptibility to Avr1 corresponding to a 1:2:1 ratio for a single hemizygous insertion. Transgene presence and expression correlated with the phenotype. The resistance phenotype expressed by Lr1 seemed therefore to be dependant on the zygosity status. T (3)-938 sister lines with and without the transgene were further tested with 16 virulent and avirulent rust isolates. Rust reactions were all as expected for Lr1 thereby providing additional evidence toward the Lr1 identity of RGA567-5. Sequence analysis of Lr1 indicated that it is not related to the previously isolated Lr10 and Lr21 genes and unlike these genes, it is part of a large gene family.